concealed in a wall or partition

A new series of Regulations (522.6.6 – 522.6.8) have been introduced in the 17th Edition of the IEE Wiring Regulations concerning cables concealed in a wall or partition. These new Regulations introduce the concept of skilled person, instructed person and ordinary person.
It is now a requirement to protect cables concealed in a wall or partition (at a depth of less than 50 mm) by a 30 mA RCD where the installation is not intended to be under the supervision of a skilled or instructed person where other methods of protection, including the use of cables with an earthed metallic covering, earthed conduit/trunking or mechanical protection, cannot be employed. Irrespective of the depth, a cable in a partition where the construction includes metallic parts other than fixings shall be protected by a 30 mA RCD. For example, this means that in a domestic installation, where insulated and sheathed cables are concealed in a wall at a depth of less than 50 mm and have no mechanical protection, they need to be installed within the safe zones and protected by a 30 mA RCD.

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Skilled person: A person with technical knowledge or sufficient experience to enable him/her to avoid dangers which electricity may create. Instructed person A person adequately advised or supervised by skilled persons to enable him/her to avoid dangers which electricity may create.
Ordinary person: A person who is neither a skilled person nor an instructed person.
To conform with the requirements of BS 7671, wiring systems must utilize cables complying with the relevant requirements of the applicable British Standard or Harmonized Standard. Alternatively, if equipment complying with a foreign national standard, based on an IEC Standard is to be used, the designer or other person responsible for specifying the installation must verify that any differences between that standard and the corresponding British Standard or Harmonized Standard will not result in a lesser degree of safety than that afforded by compliance with the British Standard.
The effect of environmental conditions and general characteristics around various parts of the installation must be assessed to enable suitable electrical equipment, including the wiring system, to be specified. For example, cables and equipment used in agricultural and horticultural premises should be installed away from areas or routes used by animals or be of a type to withstand such attack. Any part of the fixed installation which may be exposed to a severe impact must be able to survive it. In workshops, for example, where heavy objects are moved, installation of wiring systems in traffic routes should be avoided or localized protection must be provided. Therefore, when designing a concealed installation, the designer must select a suitable wiring system. Under the 17th Edition, depending on the type of wiring selected, the method of installation and whether the installation will be under the control of a skilled person, or instructed person or ordinary person will depend whether the concealed wiring will require RCD protection or not. For example, in a domestic installation, where insulated and sheathed cables are concealed in a wall at a depth of less than 50 mm and have no mechanical protection, they need to be installed within the safe zones and need to be protected by a 30 mA RCD. Regulations 522.6.6 and 522.6.8 are reproduced here for information. 522.6.6 A cable concealed in a wall or partition at a depth of less than 50 mm from a surface of the wall or partition shall:
(i) Incorporate an earthed metallic covering which complies with the requirements of these Regulations for a protective conductor of the circuit concerned, the cable complying with BS 5467,BS 6346, BS 6724, BS 7846, BS EN 60702-1 or BS 8436, or
(ii) Be enclosed in earthed conduit complying with BS EN 61386 and satisfying the requirements of these Regulations for a protective conductor, or
(iii) Be enclosed in earthed trunking or ducting complying with BS EN 50085 and satisfying the requirements of these Regulations for a protective conductor, or
(iv) Be mechanically protected against damage sufficient to prevent penetration of the cable by nails, screws and the like, or
(v) Be installed in a zone within 150 mm from the top of the wall or partition or within 150 mm of an angle formed by two adjoining walls or partitions. Where the cable is connected to a point, accessory or switch gear on any surface of the wall or partition, the cable may be installed in a zone either horizontally or vertically, to the point, accessory or switch gear. Where the location of the accessory, point or switch gear can be.

Upgrading your boiler

Upgrading your boiler from ETM
How old is your central heating boiler? If it’s more than 10 years old, it may be time to think about replacing it with a new high efficiency model
You could get this work funded by a grant.
Today’s central heating boilers are much better than the old ones. They can heat water more efficiently, meaning they use less gas or oil to do the same job. This saves energy and will save you money. In fact, if your boiler is over 10 years old, then it’s probably worth investing in a new one. In most cases the savings you make from a more efficient boiler over the years will pay for the outlay.
Building regulations stipulate that if you are replacing an old boiler the new appliance must be A-rated for energy efficiency.
This means it must be at least 88% efficient (most new boilers score over 90%), and to reach this level it will almost certainly be one of the new-style condensing boilers.
The technical bit
Condensing boilers are more efficient because they extract the heat from the exhaust gases (or ‘flue gases’) that all boilers produce. What makes this possible is a second heat exchanger where the water vapour in the flue gas condenses into droplets of liquid water, releasing heat as it does so. The condensed liquid water drains away through a pipe installed specifically for this purpose. Non-condensing boilers simply expel the gases into the air and the heat is wasted.
You’ll notice that the vapour that comes out of a condensing boiler’s flue forms a visible plume of ‘steam’ (actually a mixture of water vapor and other gases). This is perfectly normal and is an indication that the gases are cooler than those vented by non-condensing boilers.
‘Combi’ boilers
Condensing boilers come in both combination and regular models. A combination (or ‘combi’) boiler will provide your central heating and produce hot water on demand, firing up when you turn on a hot tap in the kitchen or bathroom. A regular boiler will do your central heating, but rather than produce hot water as and when required, it will heat a quantity of water which is held in a storage cylinder until required.
Some boilers only run the central heating and don’t provide hot water at all, in which case an electric immersion tank or another form of water heating is required.
In a typical semi-detached property that uses mains gas for heating you can reduce your heating bills by around £300 per year if you upgrade from an old G-rated boiler (less than 70% efficient) to a new A-rated condensing boiler with full heating controls (e.g. timer/programmer, room thermostat and thermostatic radiator valves). The savings are even greater for larger properties and for heating systems that run on oil which is more expensive than gas.
Flue gas heat recovery
A flue gas heat recovery system can make boilers more efficient by capturing and re-using heat energy that would otherwise have escaped out of your flue or chimney. All boilers which burn fuel to produce heat create exhaust gases, and these need to be expelled outside. However, as these gases are are hot (about 200°C), as much as 35% of the heat being produced by the boiler can be wasted when they are expelled.
This system also uses the hot flue to pre-heat the cold water being fed into the boiler. This means the boiler does not need to work as hard to provide you with hot water. Flue gas heat recovery systems significantly improve the performance of condensing boilers, with many achieving efficiency

central heating boilers
central heating
of 90% and above. This means they use less gas (or oil), saving you money on your bills.
So, what do I do now?
If you decide to go for a new boiler, you should get at least three quotes from qualified heating engineers. These should be on the Gas Safe Register or registered with OFTEC for oil-fired systems as it is illegal and also potentially extremely dangerous for someone who is not fully qualified to fit a central heating boiler.
Both Gas Safe and OFTEC have lists of registered installers which you can access by phone or online. An installer registered with a competent person scheme will also be able to self-certify that the work is compliant with the building regulations:
Gas Safe Register is the official list of gas engineers who are registered to work safely and legally on gas appliances. Always check your engineer is on the Gas Safe Register.
0800 408 5500 |
OFTEC represents the interests of homeowners, registered technicians and trade association members, providing advice and information on oil fired heating and cooking.
0845 65 85 080 |
Competent Persons Schemes were introduced to allow individuals and enterprises to self-certify that their work complies with the Building Regulations as an alternative to submitting a building notice or using an approved inspector.
Your new boiler should have a power-flush (or a mains pressure flush for some models) to remove sludge and other deposits from the system which could damage the new boiler. The installer may also add lime scale inhibitors or water softeners to prevent the build up of lime scale. The boiler should be serviced annually to ensure that it stays in good working order and maintains its efficiency.
Plan for replacement
No one wants to go without heating and hot water in the winter, so it makes sense to plan the replacement of your boiler rather than waiting for it to break down. It also means that you can take your time to shop around for quotes rather than having to get an emergency replacement in a rush. And remember, heating engineers tend to be busier in the winter so if your boiler breaks down then, you may have a long wait before someone can come to your home to install a new one.
If ETM can help with any further queries please phone our friendly team on 01922 710014 or pop in to see us we have free parking and large amount of boilers on display.

electrical safety testing

One good reason for carrying out electrical safety testing on your building. Loose connections found wile carrying out electrical safety testing at one of our clients site.

Loose connections could cause a fire, this fault would be classed as a C1 Fail Code -Danger Present. Risk of injury. Immediate remedial action required.

The Electricity at Work Regulations 1989-Reg 4(2) state “The need for maintenance to be done to ensure safety”. As such all commercial premises must be electrically tested and certified to ensure they can continue to be used safety.

BS7671 wiring regulations to the latest edition sets out the requirements for all electrical installations in the UK. The Institute of Engineers and Technology (IET) produce guidance notes to enlarge on the wiring regulations and set out guidance on how compliance can be achieved. Guidance Note 3 covers the Inspection & testing of Electrical Installations.

An electrical installation should be periodically inspected by a qualified electrical engineer. ETM (Electrical Test Midlands) are experts in this field and will advise any customer who may be unsure of the periodicity or scope of the Inspection & Test.

For more information on electrical testing please phone us on 01922 710014

or use our free phone number 0800 066 3227